Wind Tunnel Study on a Missile with Forward-Facing Cavity in Supersonic Flow

2014 ◽  
Vol 1016 ◽  
pp. 370-376
Author(s):  
Jiang Zhang ◽  
Xiao Jun Pan ◽  
Jin Gang Dong ◽  
Yong Ming Qin ◽  
Han Dong Ma
Keyword(s):  
Wind Tunnel ◽  
Total Pressure ◽  
Force Measurement ◽  
Cavity Flow ◽  
Bow Shock ◽  
Dynamic Force ◽  
Flow Conditions ◽  
Fluctuation Pressure ◽  
Wind Tunnel Study ◽  
Transonic Wind Tunnel

A forward-facing cavity will be composed of the components of a scramjet from inlet to combustion chamber which has a uncovered inlet before the separation of the booster. Longitudinal oscillations are generated within the cavity under some certain flow conditions. Strong oscillations may damage the components of the scramjet, or induce bow-shock oscillations which may cause unsteady loads on the missile and affect the performance of the aerodynamical characteristics. An experimental study of missile model with a scramjet was conducted in a transonic wind tunnel. The characteristics of cavity flow were researched by both the dynamic force measurement and the fluctuation pressure measurement. In the experiments the oscillations within the cavity and the bow-shock in front of the inlet interacted. The oscillations of cavity flow and bow-shock affected the fluctuation pressure and the aerodynamical characteristics of missile remarkably. The amplitude of axial force was higher than the normal force's. The RMS of the fluctuation pressure of some measured place inside the scramjet reached a quarter of the total pressure, and the amplitude of the fluctuation reached half of the total pressure. Those might threaten the safety of the structure of the scramjet.

scholarly journals Relativity Research of Total Pressure and Regulating Valve in Continuous Wind Tunnel and Its Application

2020 ◽  
Vol 38 (2) ◽  
pp. 325-332
Author(s):  
Dan Chen ◽  
Xiaosong Yang ◽  
Gang Li ◽  
Shouchun Guo ◽  
Tianyi Chen
Keyword(s):  
Wind Tunnel ◽  
Flow Field ◽  
Total Pressure ◽  
Position Control ◽  
Flow Characteristics ◽  
Field Performance ◽  
Pressure Control ◽  
Static Test ◽  
Polar Curve ◽  
Transonic Wind Tunnel

As the main adjusting means of the total pressure for the continuous transonic wind tunnel, the characteristics of regulating valve directly affect the flow field performance of the wind tunnel, therefore, it is important to analyze and establish the correlation between the regulating valve and the total pressure, and it is necessary to select the appropriate regulating valve and its combination accordingly. Firstly, in terms of the pressure regulation principle of the wind tunnel pressure regulating system, combining with the flow characteristics of the regulating valve, the correlation between the position control of the regulating valve and the total pressure control of the wind tunnel is established, then the static test is conducted to verify the relationship. In order to shorten the flow field stability time under the negative pressure of 0.6m continuous transonic wind tunnel, based on the established theory, the valve system is optimized and reformed, and the blowing test is carried out. The results show that the time of optimized Mach number polar curve decreases by 40%~50%, which greatly improves the test efficiency, which further proves that the present analysis is correct and effective, and can provide reference for the design of pressure regulating system in continuous transonic wind tunnel.

scholarly journals Assessment of high enthalpy flow conditions for re-entry aerothermodynamics in the plasma wind tunnel facilities at IRS

2021 ◽  
Author(s):  
Stefan Loehle ◽  
Fabian Zander ◽  
Martin Eberhart ◽  
Tobias Hermann ◽  
Arne Meindl ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Total Pressure ◽  
Low Earth Orbit ◽  
Specific Enthalpy ◽  
Space Systems ◽  
Flow Conditions ◽  
Experimental Conditions ◽  
High Enthalpy ◽  
The University ◽  
Boundary Layer Edge

AbstractThis article presents the full operational experimental capabilities of the plasma wind tunnel facilities at the Institute of Space Systems at the University of Stuttgart. The simulation of the aerothermodynamic environment experienced by vehicles entering the atmosphere of Earth is attempted using three different facilities. Utilizing the three different facilities, the recent improvements enable a unique range of flow conditions in relation to other known facilities. Recent performance optimisations are highlighted in this article. Based on the experimental conditions demonstrated a corresponding flight scenario is derived using a ground-to-flight extrapolation approach based on local mass-specific enthalpy, total pressure and boundary layer edge velocity gradient. This shows that the three facilities cover the challenging parts of the aerothermodynamics along the entry trajectory from Low Earth Orbit. Furthermore, the more challenging conditions arising during interplanetary return at altitudes above 70 km are as well covered.

Heuristic open-loop output feedback model predictive control for control of intermittent transonic wind tunnel

2019 ◽  
Vol 42 (4) ◽  
pp. 832-839
Author(s):  
Jianchen Hu ◽  
Baocang Ding
Keyword(s):  
Steady State ◽  
Mach Number ◽  
Wind Tunnel ◽  
Predictive Control ◽  
Output Feedback ◽  
Total Pressure ◽  
Dynamic Control ◽  
Open Loop ◽  
Feedback Model ◽  
Transonic Wind Tunnel

For intermittent transonic wind tunnel (ITWT), Mach number and total pressure are crucial features of the flow field in the test section. However, they are typically difficult to control due to system nonlinearities, uncertainties, coupling and delays. This paper proposes an output feedback model predictive control (MPC) strategy to ensure the tracking of Mach number and total pressure of the ITWT to a specified reference trajectory. The proposed approach includes open-loop prediction, steady state target calculation (SSTC) and dynamic control, where the lower layer dynamic control tracks the steady state target obtained from the upper SSTC layer. By adding an artificial disturbance in the identified linear parameter varying (LPV) model for ITWT, and utilizing the resulting LPV model in both SSTC and dynamic control layers, a heuristic open-loop output feedback MPC approach is proposed. The experimental results for the control of Mach number and total pressure for ITWT demonstrate the effectiveness of the proposed approach.

A Wind Tunnel Study Of The Interaction Between Two Sailing Yachts

2013 ◽  
Author(s):  
P. J. Richards ◽  
D. J. Le Pelley ◽  
D. Jowett ◽  
J. Little ◽  
O. Detlefsen
Keyword(s):  
Wind Tunnel ◽  
Test Section ◽  
Force Measurement ◽  
Aerodynamic Force ◽  
Force Balance ◽  
The Other ◽  
Flow Disturbance ◽  
Negative Interference ◽  
Wind Tunnel Study

The interference between two yachts sailing in several conditions is investigated in the wind tunnel by using two similar yacht models, one of which is mounted on a force balance and the other moved around the test section. The yachts were configured to sail close-hauled upwind at 20° apparent wind angle, downwind under asymmetric spinnaker at 60° and downwind under symmetric spinnaker at 120° apparent wind angle. The regions of positive and negative interference are determined through aerodynamic force measurement and flow disturbance measurement, and the sources of these effects investigated.

Identification of Wall Interference Parameters in Two-Dimensional Testing in Transonic Wind Tunnel Using the PSP Technique

2016 ◽  
Author(s):  
sergio oliveira ◽  
Ana Cristina Avelar ◽  
Henrique Leite ◽  
João Batista Pessoa Falcão Filho
Keyword(s):  
Wind Tunnel ◽  
Two Dimensional ◽  
Transonic Wind Tunnel

Numerical and Experimental Study of Turbulent Flows Around Clark Y-14 Aerofoil

2015 ◽  
Author(s):  
Kshitij Vadake ◽  
Jie Cui
Keyword(s):  
Fluid Dynamics ◽  
Wind Tunnel ◽  
Real World ◽  
Force Measurement ◽  
Test Model ◽  
Wind Tunnel Testing ◽  
Cfd Simulations ◽  
Measurement Device ◽  
Tunnel Testing

Experimental Fluid Dynamics (EFD) and Computational Fluid Dynamics (CFD) have been instrumental in Fluid Mechanics to help solve scientific and engineering problems. This research attempts to use both techniques to perform a parametric study of turbulence flow around airfoil ClarkY-14 at various velocity and angle of attack (AoA). Clark Y-14 airfoil was designed in the 1920’s. It demonstrated good overall performance at low and moderate Reynolds numbers. With the progress in the aviation field, its performance was sub-optimal for newer aircraft designs. However, with the advent of RC airplanes and model aircrafts, there is a renewed interest in this airfoil. Various research projects have been conducted using this airfoil, but there hasn’t been a combined EFD and CFD study of the performance characteristics of the airfoil itself, which still finds real world applications today. One important aspect of this research included the investigation of the effects of a Force Measurement Device/Sensor, which is typically used in scaled/full-size wind tunnels to mount the test model as well as measure the forces/moments acting on it during the testing. The presence of such a device could affect the quality of the data obtained from the wind tunnel testing when compared to a real world application scenario where the aforementioned device may not be present. To the best of the author’s knowledge, no detailed study has been published on the effects of such devices. In this study, the results with and without the measuring device were generated by using CFD simulations. The results were then compared to see to what extent the inclusion of these devices will affect the results. The methodology used for this research was experimental as well as computational. In the present research, a commercially available CFD software STAR-CCM+ was employed to simulate the flows around airfoil Clark Y-14. The experimental data was obtained from wind tunnel tests using AEROLAB Educational Wind Tunnel (EWT) and compared with the simulation data from the CFD. The two data sets were in good agreement. Both experimental and simulation results were used to understand the effects of the measurement device/sensor used in the scaled wind tunnel on the lift and drag coefficients of the airfoil. Two separate CFD simulation setups were designed to model the presence and absence of the measurement device/sensor. These setups replicated the wind tunnel setup. The airfoil was tested and simulated at different speeds as well as different AoA. The comparative study gave a useful insight on the accuracy of the CFD simulations in relation to the actual testing. The analysis of results concluded that the force measurement device/sensor had insignificant effects on the accuracy and quality of data collected through wind tunnel testing.

Sign in / Sign up

Export Citation Format

Share Document